Friday, 3 June 2011

Fizzy is FUN!!!! :)

One of the reasons I like cask beer is because it's not generally too carbonated. I actually don't care too much for over-carbonated beer, or any drink that is too fizzy for that matter. Some soft drinks can be very refreshing on a hot day, but the gassy bloated feeling created when you feel like sinking a pint of cola can be particularly unpleasant.

When I was a kid it was a real treat to have fizzy pop. Often, being in a large family, squash would be the option provided. If we were really lucky Mum would put an ice tray in the freezer compartment, but lemonade or coke was reserved for parties and was a little bit of a treat.

The vast majority of draught beer served in this country is fizzy keg. I don't care for it much, although on a very hot day a pint of good lager is very refreshingly cold and the tongue scrubbing effect of the carbonation can be just the ticket.

I try to produce my keg, which I have to point out is currently very much in development, with a low level of carbonation and with minimal, if any filtering. I've been told by some craft beer people that it's not fizzy enough. Perhaps the new generation of craft keg lovers are looking for fizzy beer with flavour, because fizzy is fun.

It's an interesting conundrum; people expect keg to be colder and more carbonated. Indeed, some beer drinkers like kegged lager because it is cold and fizzy. Cask beer is flabby in comparison and is not cold enough. Some people like fizzy beer, and it is possible that at least a proportion of drinkers will engage with keg, especially the younger population. There is significant evidence to show that this is exactly what BrewDog are doing.

Of course, a potential problem of craft keg, even if it leaves the brewery at optimum carbonation levels, is ensuring it does not pick-up carbonation in the cellar of the pub. It's a fair concern and I'll be the first to admit that as more bars, like Port Street, Euston Tap, Sheffield Tap and many others start dispensing keg from small producers, we have to work with them to ensure gas settings and mixtures are correct for the product.

Oh, and guys, make sure your cellar is at 12 degrees and turn the gas off when the bar is closed.

12 comments:

I think you've got a tricky one there Dave. I've tried bottle conditioned beer that's got similar carbonation to cask and it does taste more like the draught version...but at the same time dull and lifeless. I really don't know why this is. Is it just because your expectations are different or is the beer really different? Maybe some blind tastings are called for...

Why turn the gas off when the bar is closed?You are not forcing more gas into the keg...the blanket is already there.Or is that complete cobblers?I'm a bit of a novice at this with regard to craft kegs !! Any help greatly appreciated.

Beer in a keg with a CO2 overpressure isn't (typically) an equilibrium system - the gas will continue to dissolve into the beer increasing the fizziness while pressure is applied. In an effort to limit this, the supply of gas should be cut off when not required.

However (particularly in part empty kegs), even with the gas supply disconnected, there's a fair bit of undissolved gas in the headspace, so some increase in fizziness is difficult to avoid.

Mixed gas systems were a major advance over simple CO2 top-pressure - a mix of CO2 and nitrogen is used with the ratio and pressure calculated so that (as near as possible) the CO2 gas will be in equilibrium with that dissolved in the beer, and the nitrogen will supply the extra pressure to push the beer out of the container. Correctly set up, CO2 uptake in the beer is minimised. However, even though Nitrogen is something like a hundred times less soluble in beer than CO2, it will continue to dissolve, and will change the beer (tending to that "nitrokeg" thing) over time. Again, by cutting off the supply when the beer is out of service, we'd hope to limit this.

Nowadays, by using little pumps to assist in moving the beer from the keg to the tap (flojet is a brand name) it's possible to set up a keg system with much lower overpressure than otherwise, ideally just balancing the pressure the keg was packaged with.But getting all this to work right can be alkward.

In things like "keykeg" the beer and the gas are separate - the beer is in a plastic bag, which is inside a plastic sphere which the gas goes into. There are cellar tank systems that work the same way, i.e. there's a bag in the tank. The idea is that gas pick up by the beer is less of a problem - assuming the bag is impermeable to the gas applied to the outer container.

Ed, totally agree that beer in bottle with the same volumes of CO2 seems lifeless when compared to cask. I am suspecting keg at lower carbonation levels will overall be less favoured by the keg fans.

Interestingly we found our Queboid on cask last night. Most of that beer we try is in bottle being 8%. It was simply splendid and we both thought much better than the more carbonated colder version.

There will be an opportunity for side by side tasting of mine and other brewers beers in an event that is being planned. I'm not sure if the venue has made it public knowledge yet, but will certainly be blogging about it if it happens.

Moonbox, in theory you are right, if the settings on the gas pressure and cellar temperature are optimal then the system should be in equilibrium and no gas will be absorbed by the beer. Jeff Rosenmeier, not for the first time, points this out in the comments on my previous post.

However, the reality is that most cellars and most gas pressures are not set up perfectly. Gas might sometimes be set slightly higher in busy pubs, for instance, to ensure the pressure keeps up during dispense. I know that pressure regulators I have can take many tens of minuets to stabilise pressure after demand has stopped.

In cold periods, if the cellar temperature drops a few degrees, the gas will dissolve more easily causing over-carbonation. This often manifests itself as fobbing lager, and the problem will be reduced by turning the gas off at night.

Finally, it's just good practice to reduce the risk of a leak emptying gas bottles overnight. Gas costs money and all pub operators should have an eye on wastage. I have been in the uncomfortable situation of having the last gas bottle empty because of a combination of a fault and leaving the gas on overnight.

A very interesting post this, Dave. We have been trialling our own keg as you know & we too are airing on the side of soft carbonation.

The intended level of serving carbonation is however out of our hands when the keg enters the cellar persons possession especially if they have a set format for dispensing all beers in the 'keg' bracket, this may lead to problems if the temperature is low & the gas pressure is high e.g. 25 PSI + for CO2, the beer will inevitably continue to force carbonate in the cellar, as colder beer takes on C02 faster than warmer beer.

Another problem can be the use of under bar crash coolers, whereby if the beer leaves the keg with what you may deem adequate carbonation at say 12 degrees Celsius it then passes through a crash cooler before the font, the cooler instantly makes the CO2 more soluble in the beer giving a softer feel at the bar making it appear 'under carbonated'. Where alternatively it could go through a 'short' coil in a remote cooler like a 'polarflow' where the beer only exposed to the ice bath briefly through a short steel coil this will help to ensure the temperature the beer hits the bar is not cold lager temperature.

This is why we've decided to put dispense guidance on the kegs so that the cellar person can dispense the beer with the level of carbonation we intend.

If you give a recommended serving pressure & instructions to turn the gas pressure off overnight the beer should remain in the state you intended it to, but I firmly believe it's up to us as brewers to give the information & liaise with licensees so that our beer IS served as we intend.

Dave's got rather more practical experience than I have. And James, Brewer, makes very good points. But unless the brewer has a good relationship with the outlet, gives them the right advice, and they act on it, there's plenty ways a keg beer can be spoiled. But does that make keg bad? Does poorly kept real ale make "cask" bad?

Stringer, no, individual cases of poor retailing of either form does not make it bad at all. I'd state that when either are done well the beer drinking experience can be fantastic. In either case it can be disastrous.

Sadly, some pubs are appalling and brewers do have a responsibility to step in and help. But this can only be of use if the publican is willing to accept help.

"I try to produce my keg, which I have to point out is currently very much in development, with a low level of carbonation and with minimal, if any filtering."

Why not just stick with cask then?

"I've been told by some craft beer people that it's not fizzy enough. Perhaps the new generation of craft keg lovers are looking for fizzy beer with flavour, because fizzy is fun."

I think "fizzy" is a tool that you (as a brewer) can use to create the beer you want. Just like pale malt, special malts, hops and yeast are. Why would you want to drink something like 77 lager from a cask when it tastes so much better with the extra chill and carbonation that you can get from a keg? People will disagree with that, but that's an issue of personal taste. I like Big Macs, the person next to me will say they're crap.

When a brewer sets out to make a beer, I think that method of dispense should receive as much consideration as grist, water treatment, hopping etc. If I want to make a massive DIPA and I think carbonation will help to improve drinkability and make the beer feel lighter - then I'll use keg as a tool to achieve that. If I want to make an oatmeal stout and I think cask with sparkler will give the thicker, creamier mouthfeel that I'm aiming for then I'll go for that. If people are then not buying your beer because they don't like it then go back to the drawing board on the recipe, considering ingredients, process and dispense as equal players in that recipe.

Basing your brewery output on method of dispense is like basing a restuarant on the type of crockery you own.

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